package com.itheima.chanlin.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.chanlin.common.BaseContext;
import com.itheima.chanlin.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
@WebFilter(urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
/*
*
* 1、获取本次请求的URI
2、判断本次请求是否需要处理
3、如果不需要处理，则直接放行
4、判断登录状态，如果已登录，则直接放行
5、如果未登录则返回未登录结果
*/
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;


        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();// /backend/index.html

        log.info("拦截到请求：{}",requestURI);

        //定义不需要处理的请求路径   白名单  重点拦截后台接口访问
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",/*文件上传测试，临时放行*/
                "/user/**",
                "/member/login",
                "/member/phone"
//                ,"/**"
        };


        //2、判断本次请求是否需要处理
        Boolean check = check(urls, requestURI);
        //3、如果 cheack = true不需要处理，则直接放行
        if(check){
            filterChain.doFilter(request,response);
            return;
        }

        //4-1、判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee")!=null) {
                log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));

                /*把empid放入单独线程存储公共空间*/
                Long empId = (Long) request.getSession().getAttribute("employee");
                BaseContext.setCurrentId(empId);

                filterChain.doFilter(request,response);
                return;
        }


        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        /*tips:import com.alibaba.fastjson.JSON;*/
        log.info("用户未登录...");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }
    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    private Boolean check(String[] urls, String requestURI) {

        for(String url:urls){

            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return  false;
    }

    @Override
    public void destroy() {

    }
}
